Research on oil-free air scroll compressor with high speed in 30 kW fuel cell

To supply the clean compressed air to a fuel cell system, an oil-free compressor is needed. The working process of the oil-free air scroll compressor and its cooling feature are discussed in this paper. A prototype, delivering 100 m 3/h and having a speed of 5000 rpm, is researched. The water from the fuel cell system is used as the lubricant of the bearings and the moving parts of the compressor. The prototype of the oil-free air scroll compressor has been designed, fabricated and tested, and the performances are satisfactory. Whatever material the scroll parts are constructed of, for example, aluminum alloy or titanium alloy, the trend of the compressor delivery with rotary speed is similar. However, the power consumption varies with the materials and the surface coating of the scroll parts because different materials and surface coating have different friction coefficients.